The right of defense can be considered as natural rights, and the most important fair trial guarantees. It is also an inherent right at the center of public individual rights. It has not only created in favor of the individual but also for the benefit of society as a whole. There is no justice when accused people do not have a full right of defense and where not possible to verify the truth. This means that enabling the accused to defend himself does not mean that the punishment is over, but means to emphasize the fundamental pillar of justice that will reassure the individuals to the proper functioning of mechanisms in carrying out its mission, and this would remove any doubts about injustice suspicion when Jurisdiction will announce the accused conviction, also removing the suspicion of complacency while deciding his innocence. Therefore, search in protecting the right of the accused to defend himself is not intellectually luxury, but generally speaking, it is searching in more accurate and the most complex legal issues, it is a dive in the depths, to stick to legitimacy in a centre of obstacles is not easy to overcome. Building on the above, we can say that the accused practice of his right to defend himself, remains inadequate to achieve the purpose if it is not criminally reinforced. And to enable the exercise of the right of accused to defend himself, the penal legislator decided to develop a set of substantive rules incriminating and justified, meaning the dedication of this right to proceed without fear or shame. The accused is in great need to exercise his right of defense under the umbrella of the criminal protection, and this will protect him of the treachery of his defense and ensures that his rights will not be exploited because of the weakness of his position, and the lack of his experience, and the conflict hostile facing him. To find out the aspects of this protection two sections have been developed in this research: the first section devoted to the study of the criminal substantive rules, while the second was created to the study of the justified substantive rules. The aim of this is to show the criminal aspects of protection of the right of the accused to defend in court.